Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive, and not-open-world. The description adds genuinely new behavioral context beyond that: it discloses a freshness guarantee ('never cached') plus the rationale, and flags the result as 'approximate'. It falls short of stating accuracy limits or what happens on resolution failure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences, no filler, with the returned value front-loaded and the caching constraint following as supporting rationale. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter, no-output-schema tool with annotations covering safety, the description supplies what the agent needs: what is returned (city/state), its source (network edge), and its freshness guarantee. Only accuracy caveats and failure behavior are left unstated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so the baseline is 4 and there is nothing for the description to compensate for. It correctly implies the result is caller-derived rather than argument-driven.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific resource and return (the caller's approximate city/state, derived from the network edge), which disambiguates the otherwise opaque name 'local'. It does not explicitly contrast itself with any sibling, but its function is distinct enough from the lookup/consulta tools that differentiation is not strictly needed.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: an agent can infer this is the tool to call when it needs the requester's geographic location, but there is no explicit when-to-use framing, no prerequisites, and no named alternatives or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.